1. Field of the Invention
The present invention relates generally to work vehicles having a front blade configured to push materials such as soil, sand, rubble or other debris, and, more particularly, to an apparatus for selectively coupling such a blade mechanism to a work vehicle at multiple pitch angles.
2. Description of the Related Art
Bulldozers having front blades are well known. Generally, the blade is supported by one or more hydraulic cylinders used to push the blade forward and/or alter the pitch of the blade. Other bulldozers have a blade with a static pitch where an operator must disengage and re-engage the blade in order to alter the pitch angle of the blade relative to the frame and/or bulldozer.
In prior art systems for static pitch bull dozers, a single mounting bore is disposed through an anchoring bracket on the rear of the blade and multiple, linearly arranged corresponding mounting bores are disposed on one end of an adjacent pitch link. The pitch of the blade is adjusted by selectively engaging the pitch link with a mounting bore on the mounting bracket. Such systems often include a plurality of retention holes disposed through the anchoring bracket relatively adjacent to the mounting bores.
Other prior art systems can include a plurality of linearly arranged mounting bores through an anchoring bracket on the top of the push beam of the bulldozer. These systems can also have a plurality of retention holes disposed through the anchoring bracket relatively adjacent to the mounting bores.
In both of the above described prior art designs, each retention hole adds to the cost of manufacturing the bulldozer. Additionally, any unused retention holes are open to the elements as the bulldozer is in use. Consequently, the retention holes are susceptible to oxidation which may render the retention hole unusable. Also, systems with mounting bores on the top of the push beam of the bulldozer are more susceptible to damage than arrangements on the back of the blade.
Other prior art bulldozer blade assemblies require the use of an extendable turnbuckle. Extendable turnbuckles also add complexity to the overall design. Moreover, dirt and debris collected while using the bulldozer may negatively impact the functionality of such extendable turnbuckles. The extension mechanism of such turnbuckles is also susceptible to damage from oxidation.
Thus, what is needed is an improved system for selectively mounting a blade at a desired pitch angle on a bulldozer.